85 Johnson 235 Peak RPM

[dhym]

I have 235 and am wondering what peak RPM should be.

19 Pitch Prop - 5700 rpm 45 mph
21 Pitch Prop - 5200 rpm 52 mph

Are these number right?

 

[angus63]

Re: 85 Johnson 235 Peak RPM

Popular opinion is to shoot for appx 5800 rpm. Looks like your rig likes the 19" pitch prop.

 

[Molaker]

Re: 85 Johnson 235 Peak RPM

I can't tell from info available which prop is best. True, you do want WOT to be about 5500-5800 but IMHO, there is a bit more to the formula. If you are simply comparing the props without trimming up to max RPM just below the start of porpoising or ventilation, you might be comparing apples to oranges.